Electrical signaling



May 19, 1925. 1,538,570

L. COHEN ET AL ELECTRICAL SIGNALING Filed June 16, 1920 2 Sheets-Sheet l Defecfow pd] W1) )H) Him hwwm v 8% WM May ,19, 1925. 1,538,570

L. COHEN ET AL ELECTRICAL S IGNALING Filed Ju ne 16, 1920 2 Sheets-Sheet 2 Dlzclor the coil, so that in either case Patented May 19, 1925.

UNITED STATES I 1,538,570 ATENT; OFFICE.

LOUIS COHEN AND JOSEPH O. MAUBORGNE, OF WASHINGTON, DISTRICT OF COLUMBIA.

ELECTRICAL SIGNALING.

Application filed. June 16, 1920. Serial No. 389,451.

To all whom it may concern:

Be it known that we, LoUIs Comm and JOSEPH ,O. MAUBORGNE, citizens of the United States, residing 1n Washington, in the District of Columbia, have invented certain new and useful Improvements in. Electrical Signaling, of which the'following is a specification,

This invention relates to the art of radio signaling, and particularly receiving radio signals, and a system for use in practicing the same.

The object of the present invention is an improvement in the method and apparatus for the reception of radio signals, securing thereby better tuning, reducing interference effects, and efiecting a simplification in the equipment required.

In the present practice of the art tuning is accomplished by the use of inductance coils and condensers so adjusted as to be in resonance for the frequency of the signals to be received. To obtain sharp tuning so as to reduce interference from foreign signals to a minimum, a complicated network of circuits is usually r uired making it relatively expensive and ifiicult to handle in the matter of adjustments.

In this invention the tuning is accomplished by the use of a resonance wave coil on which a wave development is produced by the incoming signals, and the detector connection adjusted to the point of the loop of potential, or the loop otcurrent of the wave developed on the coil, depending on the type of connection used. The resonance wave coil is preferably made in the form of a long helix, all the electrical constants of which, inductance, capacity and resistance, are of a distributed character. The coil is wound with a large number of turns of insulated wire per unit length, and the winding ma be either single layer or multiple layer, t e, object being to secure large mductance per unit length so as to get'in a com aratively short length the equivalent con ition of a. long line in the matter of wave development. The wave length ad-- justment for different signal frequencies is accomplished by either varying the len h of the coil or by changing one of the e cotrical constants, preferably the capacity, of the natural wave length of the antenna system would corres nd to the wave length of the signals desire to receive.

ring moving along The resonance wave coil may be used either with or without an antenna. In the latter case the coil functions as the antenna as well as the tuning element, the coil by itself constituting the complete receiving equipment.

The principle of operation and the method of using our invention can be better understood by areference to the accompanying diagrammatic figures which show typical embodiments of the invention and form part of this specification.

In the accompanying drawings:

' Figure 1 is a diagrammatic v ew of a system for carrying out the invention in which the natural wave length of the antenna and wave coil system is varied by moving a grounded metal tube over the wave coil;

Fi re 2 is similar to Figure 1, showing the etector connected to a point on the coil and to ground;

Figure 3 is a diagrammatic view of an arrangement for carrying out our invention in which the natural wave length of the antenna and wave coil system is varied by shifting the ground connection on the wave co1 V Figure l shows another embodiment of our invention in which coupled circuits are employed, in each of which a resonance wave coil is used.

Figure 5 is a schematic view showing an untuned coupled circuit;

Figure 6 shows anarrangement in which the variation of the electrical constants of the Wave coil is obtained by m'ovin a grounded metal tube inside the coil; an

Figure 7 shows still another modification of our invention in which no antenna is used; the wave coil with a grounded metal tube sliding over it constituting the complete antenna system.

, Having more particular reference to the drawings, and in connection with which like characters of reference will desi resonance wave coil and a metal tube plate or narrow metal the. coil axially and is 8' to the detector (6 e' capacity .per umt art of the coil which is inclosed in the tu is much greater than the designates. a metal connected by'wire at' the point ,(7).

length of, that I ate corre- 'sponding parts throughout, in i re 1 the antenna (1) is connected direct y to the part of the coil outside the tube. The natural wave length of the coil as a whole would therefore depend on the relative lengths of the parts of the coil which are in the metal tube and outside of it. By

moving-the metal tube (3) along the c011 (2) so as to inclose a greater or smaller part of it, the natural wave length of the coil is altered; also the position of the tube on the coil, that'is, whether at the end of the coil or at the middle part of the coil would have .an efi'cct on the capacity distribution of the coil and consequently affect the naturalwave length of the 0011. This evidently affords a means of adjusting the wave length of the antenna and wave coil system so as to bring 'it into resonance with the wave length of the signals desired to receive. The metal plate (5) serves as an electrostatic connection between the coil (2) and the detector (6). The plate (5) is adjusted along the axis of the coil for the point of the loop of potential for maximum sensitiveness. In this arrangement a unilateral connection to the detector is shown. (6)

designates the electron tube amplifier and I detector, and (7 is the input grid'terminal of said amplifier.

Accordin to Figure 2 the detector (6) is connecter? directly to a point (5 on the wave coil (2), the connecting point beingadjustable along the coil; the other terminal of the detector (9), which in the case of an electron tube is a filament, connected at (10) and by lead (11) to the ground 4). The rinci le of operation is similar to t at described or Figure 1.

Another embodiment of the invention is shown in Figure 3. The natural wave length of antenna and wave coil system is changed by varying the amount of the coil included in the antenna circuit 1, 2, 10, 11 and 4, which is accomplished by moving the connection (10) along the coil.

In Figure 4 a coupled circuitarran ement is shown in which the antenna circuit 1, 2, 3, 10 and 4 and the secondary circuit 16, 2', 3, 10', and 4 are separately tuned b a resonance wave coil, in the manner descri ed in connection with Fi ure 1. In both circuits a grounded meta tube slides over the resonance wave coil, thereby adjusting the natural wave length of each system to correspond to the Wave length of the incoming a grounde of any electron tube detector, leaving the other terminal open, or the two terminals connected to (7) and (9), the grid and filament resp ctively of an electron tube detector, as shown in the figure.

Figure 6 is similar to Figure 1 except that a variation of the electrical constants of the resonance wave coil to produce a change inthe natural wave length of the antenna and wave coil s stem is accomplished by placing metal tube (3 inside the coil and effecting a change in t e electrical constants of the coil by moving the metal tube in or out of the coil, the method and principle of o eration being the .same as that described or Figure 1.

In Figure 7, an arrangement is shown for receiving radio signals in which the resonance wave coil (2) serves as the antenna for picking u the ener of the incoming signals, as we 1 as being t e tuning element.

In this case also the tuning is accomplished by shifting the metal tube (3) along the axis of the coil (2) thus varying the natural wave length of the coil.

We claim:

system of receiving radio signals comprising an antenna, a resonance wave coil, an adjustable grounded metal tube operatively associated with said resonance wave coil, a secondary circuit coupled to said resonance wave coil, and an indicating de vice connected to said secondary circuit.

2. A system ofreceiving radio signals comprising an antenna, a resonance wave coil and an adjustable grounded metal tube slidin over said resonance wave coil, a secon ar circuit, and a resonance wave coil of varia 1e wave length in said secondary circuit, said secondary circuit being coupled to the resonance wave coil of thej'antenna circuit.

J. O. MAUBORGNE. LOUIS COHEN. 

